/* ============================================================
   TrustFed-SDN — project site
   Palette inspired by the CyberDome reference theme:
   near-black base, single crimson→orange accent gradient.
   ============================================================ */

:root {
  --bg:            #0A0A0F;
  --bg-alt:        #101018;
  --surface:       #14141D;
  --surface-2:     #1B1B26;
  --border:        #262631;
  --text:          #F3F4F8;
  --text-dim:      #9096A8;
  --text-faint:    #5F6577;

  --accent-1:      #E8123C;   /* crimson  */
  --accent-2:      #FF7A1A;   /* orange   */
  --accent-grad:   linear-gradient(100deg, var(--accent-1) 0%, var(--accent-2) 100%);

  --font-head:     'Space Grotesk', sans-serif;
  --font-body:      'Inter', sans-serif;
  --font-mono:      'JetBrains Mono', monospace;

  --radius:         10px;
  --max:            1180px;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

img { max-width: 100%; display: block; }

a { color: inherit; text-decoration: none; }

ul, ol { padding-left: 1.2em; margin: 0; }
li { margin-bottom: 0.5em; }

/* faint grain texture over everything, very subtle */
.grain {
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 999;
  opacity: 0.025;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='120' height='120'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='2' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
}

.accent-dot { color: var(--accent-2); }

.grad-text {
  background: var(--accent-grad);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

/* ============ BUTTONS ============ */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 13px 26px;
  border-radius: 999px;
  font-family: var(--font-body);
  font-weight: 600;
  font-size: 0.95rem;
  border: 1px solid transparent;
  transition: transform 0.15s ease, opacity 0.15s ease, border-color 0.15s ease;
  cursor: pointer;
}
.btn:hover { transform: translateY(-1px); }

.btn-primary {
  background: var(--accent-grad);
  color: #fff;
}
.btn-primary:hover { opacity: 0.92; }

.btn-ghost {
  background: transparent;
  border-color: var(--border);
  color: var(--text);
}
.btn-ghost:hover { border-color: var(--accent-2); }

/* ============ NAV ============ */
.nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  background: transparent;
  border-bottom: none;
  padding: 22px 0;
  pointer-events: none;
  transform: translateY(0);
  opacity: 1;
  transition: transform 0.55s cubic-bezier(0.22, 1, 0.36, 1), opacity 0.45s ease;
  will-change: transform, opacity;
}

.nav.nav-hidden {
  transform: translateY(-140%);
  opacity: 0;
  pointer-events: none;
  transition: transform 0.5s cubic-bezier(0.4, 0, 0.2, 1), opacity 0.4s ease;
}

.nav-inner {
  max-width: var(--max);
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  pointer-events: auto;
}

/* Outer Glassmorphic Capsule Container */
.nav-links {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 8px;
  background: rgba(16, 17, 26, 0.78);
  backdrop-filter: blur(24px) saturate(200%);
  -webkit-backdrop-filter: blur(24px) saturate(200%);
  border: 1px solid rgba(255, 255, 255, 0.22);
  border-radius: 9999px;
  box-shadow:
    0 16px 40px -4px rgba(0, 0, 0, 0.7),
    inset 0 1px 1px 0 rgba(255, 255, 255, 0.45),
    0 0 30px rgba(255, 122, 26, 0.22),
    0 0 2px rgba(255, 255, 255, 0.35);
}

/* Individual Glassmorphic Menu Buttons */
.nav-links a {
  font-family: var(--font-head);
  font-size: 0.9rem;
  font-weight: 600;
  color: #FFFFFF;
  text-decoration: none;
  padding: 8px 22px;
  border-radius: 9999px;
  border: 1px solid rgba(255, 255, 255, 0.15);
  background: rgba(255, 255, 255, 0.05);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  letter-spacing: 0.01em;
  transition: all 0.25s cubic-bezier(0.16, 1, 0.3, 1);
  white-space: nowrap;
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.16);
  text-shadow: 0 1px 2px rgba(0, 0, 0, 0.6);
}

.nav-links a:hover {
  color: #FFFFFF;
  background: rgba(255, 255, 255, 0.14);
  border-color: rgba(255, 122, 26, 0.65);
  transform: translateY(-2px);
  box-shadow:
    0 6px 20px rgba(0, 0, 0, 0.4),
    0 0 18px rgba(255, 122, 26, 0.45),
    inset 0 1px 1px rgba(255, 255, 255, 0.35);
}

.nav-links a.active {
  color: #FFFFFF;
  font-weight: 700;
  background: linear-gradient(135deg, rgba(232, 18, 60, 0.45) 0%, rgba(255, 122, 26, 0.65) 100%);
  border-color: rgba(255, 180, 110, 0.9);
  box-shadow:
    0 4px 18px rgba(255, 122, 26, 0.5),
    0 0 25px rgba(255, 122, 26, 0.4),
    inset 0 1px 1px rgba(255, 255, 255, 0.6);
  text-shadow: 0 1px 4px rgba(0, 0, 0, 0.6);
}

.nav-links a::after {
  display: none !important;
}

/* Mobile Nav Toggle */
.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: rgba(18, 18, 28, 0.75);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border: 1px solid rgba(255, 255, 255, 0.15);
  border-radius: 9999px;
  cursor: pointer;
  padding: 10px 14px;
  position: absolute;
  right: 24px;
  top: 50%;
  transform: translateY(-50%);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.4);
}
.nav-toggle span {
  width: 22px; height: 2px;
  background: var(--text);
  border-radius: 2px;
}

/* ============ HERO ============ */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 150px 24px 100px;
  overflow: hidden;
  background:
    radial-gradient(ellipse 800px 500px at 50% 25%, rgba(232, 18, 60, 0.14), transparent 60%),
    radial-gradient(ellipse 700px 500px at 85% 80%, rgba(255, 122, 26, 0.10), transparent 60%),
    var(--bg);
}

.hero-canvas {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  opacity: 0.85;
  pointer-events: none;
}

.hero-inner {
  position: relative;
  z-index: 2;
  max-width: 960px;
  margin: 0 auto;
  width: 100%;
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
}

/* Proposed System Branding in Hero */
.hero-brand-block {
  display: flex;
  flex-direction: column;
  align-items: center;
  margin-bottom: 24px;
}

.hero-logo-frame {
  width: 104px;
  height: 104px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 16px;
  position: relative;
}

.hero-logo-frame::before {
  content: '';
  position: absolute;
  inset: -14px;
  background: radial-gradient(circle, rgba(255, 122, 26, 0.28) 0%, rgba(232, 18, 60, 0.14) 50%, transparent 75%);
  border-radius: 50%;
  filter: blur(12px);
  z-index: -1;
  pointer-events: none;
}

.hero-main-logo {
  width: 92px;
  height: 92px;
  object-fit: contain;
  filter: drop-shadow(0 0 16px rgba(255, 122, 26, 0.5));
  transition: transform 0.35s ease, filter 0.35s ease;
}

.hero-main-logo:hover {
  transform: scale(1.08) translateY(-2px);
  filter: drop-shadow(0 0 24px rgba(255, 122, 26, 0.75));
}

.hero-system-name {
  font-family: var(--font-head);
  font-size: clamp(2.8rem, 6.5vw, 4.8rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.05;
  margin: 0;
  color: var(--text);
  text-shadow: 0 4px 30px rgba(0, 0, 0, 0.6);
}

.hero-badges {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 10px;
  margin-bottom: 24px;
}
.badge {
  padding: 7px 16px;
  border-radius: 999px;
  border: 1px solid var(--border);
  background: rgba(255,255,255,0.02);
  font-size: 0.8rem;
  font-weight: 500;
  color: var(--text-dim);
}

.hero-title {
  font-family: var(--font-head);
  font-size: clamp(1.35rem, 2.6vw, 1.95rem);
  font-weight: 600;
  line-height: 1.35;
  letter-spacing: -0.01em;
  max-width: 860px;
  margin: 0 0 20px;
  color: var(--text);
}

.hero-sub {
  max-width: 720px;
  color: var(--text-dim);
  font-size: 1.05rem;
  margin: 0 0 36px;
  line-height: 1.7;
}

.hero-cta {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
  margin-bottom: 56px;
}

.hero-meta {
  display: flex;
  justify-content: center;
  align-items: flex-start;
  gap: 48px;
  width: 100%;
  max-width: 960px;
  border-top: 1px solid var(--border);
  padding-top: 28px;
  text-align: center;
}
.hero-meta-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  min-width: 180px;
}
.hero-meta-label {
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-faint);
  font-weight: 600;
}
.hero-meta-value {
  font-size: 0.94rem;
  color: var(--text);
  font-weight: 500;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
  line-height: 1.45;
}
.hero-meta-value span {
  font-size: 0.94rem;
  font-weight: 500;
  color: var(--text);
  white-space: nowrap;
}
.hero-meta-value .hero-meta-sub {
  font-size: 0.82rem;
  color: var(--text-dim);
  font-weight: 400;
  white-space: normal;
}

/* ============ SECTIONS ============ */
.section {
  padding: 100px 24px;
  border-top: 1px solid var(--border);
}
.section.alt { background: var(--bg-alt); }

.section-inner {
  max-width: var(--max);
  margin: 0 auto;
}

.section-head { margin-bottom: 32px; max-width: 640px; }

.section-title {
  font-family: var(--font-head);
  font-size: clamp(1.7rem, 3vw, 2.3rem);
  font-weight: 600;
  margin: 0 0 12px;
}

.section-lede {
  color: var(--text-dim);
  font-size: 1.02rem;
  margin: 0;
}

/* Abstract split layout */
.split {
  display: grid;
  grid-template-columns: 300px 1fr;
  gap: 60px;
}
.split-head { align-self: start; }
.split-body p { color: var(--text-dim); margin: 0 0 18px; max-width: 720px; }
.split-body strong { color: var(--text); }

/* Diagram blocks (Methodology / Workflow) */
.diagram-block {
  display: grid;
  grid-template-columns: 1.3fr 1fr;
  gap: 40px;
  align-items: flex-start;
}
.diagram-block.reverse {
  grid-template-columns: 1fr auto;
  gap: 48px;
  align-items: flex-start;
}
.diagram-block.reverse .diagram-frame {
  order: 2;
  justify-self: end;
}
.diagram-block.reverse .diagram-desc {
  order: 1;
}

.workflow-head {
  margin-bottom: 20px;
}
.workflow-lede {
  margin-bottom: 20px !important;
  font-size: 1.04rem;
}

.diagram-frame {
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px;
  background: var(--surface);
}
.diagram-frame.narrow {
  max-width: 320px;
  width: 100%;
  padding: 12px;
  margin: 0;
}
.diagram-frame.narrow img {
  border-radius: 4px;
  width: 100%;
  height: auto;
  display: block;
}

.diagram-desc p { color: var(--text-dim); margin: 0 0 20px; }

.check-list { list-style: none; padding: 0; }
.check-list li {
  position: relative;
  padding-left: 26px;
  color: var(--text-dim);
  font-size: 0.94rem;
}
.check-list li::before {
  content: "";
  position: absolute;
  left: 0; top: 7px;
  width: 14px; height: 14px;
  border-radius: 3px;
  background: var(--accent-grad);
}

.step-list { list-style: none; padding: 0; counter-reset: step; }
.step-list li {
  position: relative;
  padding-left: 38px;
  color: var(--text-dim);
  font-size: 0.94rem;
  counter-increment: step;
}
.step-list li::before {
  content: counter(step);
  position: absolute;
  left: 0; top: -1px;
  width: 24px; height: 24px;
  border-radius: 50%;
  border: 1px solid var(--border);
  color: var(--text);
  font-family: var(--font-mono);
  font-size: 0.72rem;
  display: flex;
  align-items: center;
  justify-content: center;
}
.step-list li span {
  color: var(--text);
  font-weight: 600;
}

/* ============ REFERENCES ============ */
.ref-list {
  display: flex;
  flex-direction: column;
  border-top: 1px solid var(--border);
}
.ref-row {
  display: grid;
  grid-template-columns: 48px 1fr 90px;
  align-items: center;
  gap: 20px;
  padding: 24px 18px;
  border-bottom: 1px solid var(--border);
  transition: background 0.15s ease;
}
.ref-row:hover { background: var(--surface); }
.ref-row:hover .ref-go { color: var(--accent-2); }
.ref-row:hover .ref-title { color: var(--accent-2); }

.ref-index {
  font-family: var(--font-mono);
  color: var(--text-faint);
  font-size: 0.85rem;
}
.ref-body { display: flex; flex-direction: column; gap: 6px; }
.ref-title {
  font-weight: 600;
  font-size: 0.98rem;
  transition: color 0.15s ease;
}
.ref-meta {
  font-size: 0.82rem;
  color: var(--text-dim);
}
.ref-go {
  justify-self: end;
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--text-dim);
  font-family: var(--font-mono);
  transition: color 0.15s ease;
}

/* Hidden references by default */
.ref-extra {
  display: none;
}
.ref-list.expanded .ref-extra {
  display: grid;
  animation: refSlideDown 0.35s cubic-bezier(0.16, 1, 0.3, 1) forwards;
}

@keyframes refSlideDown {
  from {
    opacity: 0;
    transform: translateY(-8px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* See all / See less Toggle Button */
.ref-actions {
  display: flex;
  justify-content: center;
  margin-top: 32px;
}
.ref-toggle-btn {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 11px 26px;
  border-radius: 9999px;
  background: var(--accent-2);
  border: 1px solid transparent;
  color: #FFFFFF;
  font-family: var(--font-head);
  font-size: 0.92rem;
  font-weight: 600;
  cursor: pointer;
  transition: transform 0.2s ease, opacity 0.2s ease;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.15);
}
.ref-toggle-btn:hover {
  opacity: 0.92;
  transform: translateY(-2px);
  color: #FFFFFF;
  box-shadow: 0 4px 14px rgba(0, 0, 0, 0.20);
}
.ref-toggle-btn:active {
  transform: translateY(0);
}
.ref-toggle-icon {
  color: #FFFFFF;
  transition: transform 0.3s cubic-bezier(0.16, 1, 0.3, 1);
}
.ref-toggle-btn.expanded .ref-toggle-icon {
  transform: rotate(180deg);
}

/* ============ TEAM ============ */
.team-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}
.team-card {
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px;
  background: var(--surface);
  text-align: center;
}
.team-card.highlight {
  border-image: var(--accent-grad) 1;
  background: var(--surface-2);
}
.team-role {
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--accent-2);
  font-weight: 700;
  display: block;
}
.team-name {
  font-family: var(--font-head);
  font-size: 1.2rem;
  margin: 10px 0 4px;
}
.team-id {
  font-size: 0.85rem;
  color: var(--text-faint);
  margin: 0 0 14px;
  font-family: var(--font-mono);
}
.team-desc {
  font-size: 0.9rem;
  color: var(--text-dim);
  margin: 0;
}

/* ============ TEAM PHOTO FRAME ============ */
.team-photo-frame {
  position: relative;
  width: 132px;
  height: 132px;
  margin: 0 auto 20px;
}

/* rotating gradient verification ring */
.team-photo-ring {
  position: absolute;
  inset: 0;
  border-radius: 50%;
  background: conic-gradient(
    from 0deg,
    var(--accent-1),
    var(--accent-2),
    var(--accent-1)
  );
  animation: teamRingSpin 6s linear infinite;
  opacity: 0.9;
}

@keyframes teamRingSpin {
  to { transform: rotate(360deg); }
}

/* static inner circle holding the photo, sits over the ring
   with a small gap so the gradient ring reads as a border */
.team-photo-circle {
  position: absolute;
  inset: 5px;
  border-radius: 50%;
  overflow: hidden;
  background: var(--surface);
  box-shadow: inset 0 0 0 1px var(--border);
}

.team-photo-circle img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center top;
}

/* small checkmark badge, bottom-right of the circle */
.team-verified-badge {
  position: absolute;
  bottom: 2px;
  right: 2px;
  width: 26px;
  height: 26px;
  border-radius: 50%;
  background: var(--accent-grad);
  border: 2px solid var(--bg);
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 2px 10px rgba(232, 18, 60, 0.35);
}

@media (max-width: 860px) {
  .team-photo-frame { width: 108px; height: 108px; }
}

/* ============ FOOTER ============ */
.footer {
  border-top: 1px solid var(--border);
  padding: 40px 24px;
  background: var(--bg-alt);
}
.footer-inner {
  max-width: var(--max);
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 20px;
}
.footer-brand { display: flex; align-items: center; gap: 12px; }
.footer-logo {
  width: 34px;
  height: 34px;
  object-fit: contain;
  filter: drop-shadow(0 0 6px rgba(255, 122, 26, 0.25));
}
.footer-title { font-family: var(--font-head); font-weight: 600; margin: 0; font-size: 0.95rem; }
.footer-sub { margin: 0; font-size: 0.78rem; color: var(--text-faint); }
.footer-copy { font-size: 0.8rem; color: var(--text-faint); margin: 0; }

/* ============ SCROLL TO TOP BUTTON ============ */
.scroll-top-btn {
  position: fixed;
  bottom: 32px;
  right: 32px;
  width: 50px;
  height: 50px;
  border-radius: 50%;
  background: rgba(18, 18, 28, 0.75);
  backdrop-filter: blur(20px) saturate(180%);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
  border: 1px solid rgba(255, 255, 255, 0.15);
  color: var(--text-dim);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  z-index: 99;
  box-shadow:
    0 10px 30px rgba(0, 0, 0, 0.5),
    inset 0 1px 1px rgba(255, 255, 255, 0.15),
    0 0 16px rgba(255, 122, 26, 0.08);
  transform: translateY(90px) scale(0.85);
  opacity: 0;
  pointer-events: none;
  transition: all 0.4s cubic-bezier(0.16, 1, 0.3, 1);
}

.scroll-top-btn svg {
  transition: transform 0.25s ease;
}

.scroll-top-btn.show {
  transform: translateY(0) scale(1);
  opacity: 1;
  pointer-events: auto;
}

.scroll-top-btn:hover {
  transform: translateY(-4px) scale(1.08);
  color: #FFFFFF;
  background: rgba(255, 122, 26, 0.18);
  border-color: rgba(255, 122, 26, 0.6);
  box-shadow:
    0 14px 34px rgba(0, 0, 0, 0.6),
    0 0 24px rgba(255, 122, 26, 0.5),
    inset 0 1px 1px rgba(255, 255, 255, 0.2);
}

.scroll-top-btn:hover svg {
  transform: translateY(-2px);
}

.scroll-top-btn:active {
  transform: translateY(-1px) scale(0.96);
}

/* ============ THEME TOGGLE BUTTON (INSIDE NAV CAPSULE) ============ */
.nav-divider {
  width: 1px;
  height: 20px;
  background: rgba(255, 255, 255, 0.18);
  margin: 0 4px;
  flex-shrink: 0;
}

.theme-toggle-btn {
  position: relative;
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.05);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid rgba(255, 255, 255, 0.15);
  color: #FFFFFF;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  flex-shrink: 0;
  transition: all 0.25s cubic-bezier(0.16, 1, 0.3, 1);
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.16);
  padding: 0;
}
.theme-toggle-btn:hover {
  background: rgba(255, 255, 255, 0.14);
  border-color: rgba(255, 122, 26, 0.65);
  color: #FFFFFF;
  transform: translateY(-2px);
  box-shadow:
    0 6px 20px rgba(0, 0, 0, 0.4),
    0 0 18px rgba(255, 122, 26, 0.45),
    inset 0 1px 1px rgba(255, 255, 255, 0.35);
}
.theme-toggle-btn svg {
  transition: transform 0.4s ease, opacity 0.25s ease;
}
.theme-toggle-btn .icon-sun  { display: none; }
.theme-toggle-btn .icon-moon { display: block; }

@media (max-width: 860px) {
  .nav-divider {
    width: 60%;
    height: 1px;
    margin: 4px auto;
  }
  .theme-toggle-btn {
    margin: 4px auto 0;
    width: 42px;
    height: 42px;
  }
}

/* ============ LIGHT MODE ============ */
:root[data-theme="light"] {
  --bg:            #FAFAFC;
  --bg-alt:        #F2F2F6;
  --surface:       #FFFFFF;
  --surface-2:     #FFF4F0;
  --border:        #E3E3EA;
  --text:          #14141D;
  --text-dim:      #55596B;
  --text-faint:    #8A8FA3;

  --accent-1:      #E8123C;
  --accent-2:      #FF7A1A;
  --accent-grad:   linear-gradient(100deg, var(--accent-1) 0%, var(--accent-2) 100%);
}

/* Light: sun icon visible, moon hidden */
:root[data-theme="light"] .theme-toggle-btn .icon-sun  { display: block; }
:root[data-theme="light"] .theme-toggle-btn .icon-moon { display: none; }

/* Light: theme toggle button & divider */
:root[data-theme="light"] .nav-divider {
  background: rgba(20, 20, 29, 0.12);
}
:root[data-theme="light"] .theme-toggle-btn {
  background: rgba(20, 20, 29, 0.04);
  border-color: rgba(20, 20, 29, 0.08);
  color: #14141D;
  box-shadow: none;
}
:root[data-theme="light"] .theme-toggle-btn:hover {
  background: rgba(255, 122, 26, 0.10);
  border-color: rgba(255, 122, 26, 0.5);
  color: #14141D;
  box-shadow: 0 4px 14px rgba(255, 122, 26, 0.15);
}

/* Light: Glassmorphic Nav Links */
:root[data-theme="light"] .nav-links {
  background: rgba(255, 255, 255, 0.75);
  border: 1px solid rgba(20, 20, 29, 0.10);
  box-shadow:
    0 16px 40px -4px rgba(20, 20, 29, 0.12),
    inset 0 1px 1px 0 rgba(255, 255, 255, 0.6),
    0 0 30px rgba(255, 122, 26, 0.10);
}
:root[data-theme="light"] .nav-links a {
  color: #14141D;
  background: rgba(20, 20, 29, 0.04);
  border-color: rgba(20, 20, 29, 0.08);
  text-shadow: none;
  box-shadow: none;
}
:root[data-theme="light"] .nav-links a:hover {
  background: rgba(255, 122, 26, 0.10);
  border-color: rgba(255, 122, 26, 0.5);
  color: #14141D;
  box-shadow: 0 4px 14px rgba(255, 122, 26, 0.15);
}
:root[data-theme="light"] .nav-links a.active {
  color: #FFFFFF;
  background: linear-gradient(135deg, rgba(232, 18, 60, 0.9) 0%, rgba(255, 122, 26, 0.9) 100%);
  border-color: rgba(255, 122, 26, 0.6);
  text-shadow: none;
  box-shadow: 0 4px 14px rgba(255, 122, 26, 0.3);
}

/* Light: Mobile nav toggle */
:root[data-theme="light"] .nav-toggle {
  background: rgba(255, 255, 255, 0.85);
  border-color: rgba(20, 20, 29, 0.1);
}
:root[data-theme="light"] .nav-toggle span {
  background: var(--text);
}

/* Light: Mobile nav dropdown */
:root[data-theme="light"] .nav-links {
  /* mobile open state */
}
@media (max-width: 860px) {
  :root[data-theme="light"] .nav-links {
    background: rgba(255, 255, 255, 0.96);
    border: 1px solid rgba(20, 20, 29, 0.1);
    box-shadow: 0 16px 40px rgba(20, 20, 29, 0.12);
  }
}

/* Light: Scroll-to-top button */
:root[data-theme="light"] .scroll-top-btn {
  background: rgba(255, 255, 255, 0.85);
  border-color: rgba(20, 20, 29, 0.1);
  color: var(--text-dim);
  box-shadow:
    0 10px 30px rgba(20, 20, 29, 0.12),
    inset 0 1px 1px rgba(255, 255, 255, 0.5);
}
:root[data-theme="light"] .scroll-top-btn:hover {
  background: rgba(255, 122, 26, 0.1);
  border-color: rgba(255, 122, 26, 0.4);
  color: var(--accent-2);
  box-shadow:
    0 14px 30px rgba(20, 20, 29, 0.15),
    0 0 20px rgba(255, 122, 26, 0.25);
}

/* Light: Hero background */
:root[data-theme="light"] .hero {
  background:
    radial-gradient(ellipse 800px 500px at 50% 25%, rgba(232, 18, 60, 0.08), transparent 60%),
    radial-gradient(ellipse 700px 500px at 85% 80%, rgba(255, 122, 26, 0.06), transparent 60%),
    var(--bg);
}
:root[data-theme="light"] .hero-canvas {
  opacity: 0.85;
}
:root[data-theme="light"] .grain {
  opacity: 0.010;
}

/* Light: Hero text shadow */
:root[data-theme="light"] .hero-system-name {
  text-shadow: 0 2px 16px rgba(20, 20, 29, 0.08);
}

/* Light: Hero logo frame glow */
:root[data-theme="light"] .hero-logo-frame::before {
  background: radial-gradient(circle, rgba(255, 122, 26, 0.20) 0%, rgba(232, 18, 60, 0.10) 50%, transparent 72%);
  filter: blur(14px);
}

/* Light: Logo — pure gradient logo */
:root[data-theme="light"] .hero-main-logo {
  filter: drop-shadow(0 6px 20px rgba(255, 122, 26, 0.25));
}
:root[data-theme="light"] .hero-main-logo:hover {
  transform: scale(1.08) translateY(-2px);
  filter: drop-shadow(0 8px 24px rgba(255, 122, 26, 0.40));
}
:root[data-theme="light"] .footer-logo {
  filter: drop-shadow(0 2px 6px rgba(255, 122, 26, 0.20));
}

/* Light: Sections */
:root[data-theme="light"] .section {
  background: var(--bg);
}
:root[data-theme="light"] .section:nth-child(even) {
  background: var(--bg-alt);
}

/* Light: Cards/Surfaces */
:root[data-theme="light"] .card,
:root[data-theme="light"] .team-card,
:root[data-theme="light"] .fact-item {
  background: var(--surface);
  border-color: var(--border);
  box-shadow: 0 2px 16px rgba(20, 20, 29, 0.06);
}
:root[data-theme="light"] .team-card.highlight {
  background: var(--surface-2);
  border-color: rgba(255, 122, 26, 0.3);
  box-shadow: 0 4px 24px rgba(255, 122, 26, 0.12);
}

/* Light: Diagram frames */
:root[data-theme="light"] .diagram-frame {
  background: var(--surface);
  border-color: var(--border);
  box-shadow: 0 4px 24px rgba(20, 20, 29, 0.08);
}

/* Light: Ref rows */
:root[data-theme="light"] .ref-row {
  background: var(--surface);
  border-color: var(--border);
}
:root[data-theme="light"] .ref-row:hover {
  background: var(--surface-2);
  border-color: rgba(255, 122, 26, 0.3);
}

/* Light: See all references toggle button */
:root[data-theme="light"] .ref-toggle-btn {
  background: var(--accent-2);
  border: 1px solid transparent;
  color: #FFFFFF;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.12);
}
:root[data-theme="light"] .ref-toggle-btn .ref-toggle-icon {
  color: #FFFFFF;
}
:root[data-theme="light"] .ref-toggle-btn:hover {
  background: var(--accent-2);
  border-color: transparent;
  color: #FFFFFF;
  opacity: 0.92;
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.16);
}
:root[data-theme="light"] .ref-toggle-btn:hover .ref-toggle-icon {
  color: #FFFFFF;
}
:root[data-theme="light"] .ref-toggle-btn.expanded {
  background: var(--accent-2);
  border-color: transparent;
  color: #FFFFFF;
  opacity: 0.92;
}

/* Light: Footer */
:root[data-theme="light"] .footer {
  background: var(--surface);
  border-top: 1px solid var(--border);
}

/* Light: Badge */
:root[data-theme="light"] .badge {
  background: rgba(20, 20, 29, 0.05);
  border-color: rgba(20, 20, 29, 0.12);
}

/* Light: btn-ghost */
:root[data-theme="light"] .btn-ghost {
  border-color: rgba(20, 20, 29, 0.2);
  color: var(--text);
}
:root[data-theme="light"] .btn-ghost:hover {
  border-color: var(--accent-2);
}

/* Light: transition for smooth theme switch */
body, .nav-links, .scroll-top-btn, .theme-toggle-btn, .ref-toggle-btn,
.hero, .section, .card, .team-card, .fact-item,
.diagram-frame, .ref-row, .footer, .badge {
  transition:
    background 0.35s ease,
    border-color 0.35s ease,
    box-shadow 0.35s ease,
    color 0.35s ease;
}

/* ============ RESPONSIVE ============ */
@media (max-width: 860px) {
  .nav {
    padding: 24px 0 12px 0;
    transform: translateY(0) !important;
    opacity: 1 !important;
  }
  .nav-inner {
    justify-content: flex-end;
  }
  .nav-links {
    position: absolute;
    top: calc(100% + 8px);
    left: 20px; right: 20px;
    width: auto;
    border-radius: 20px;
    background: rgba(14, 14, 22, 0.94);
    backdrop-filter: blur(24px);
    -webkit-backdrop-filter: blur(24px);
    border: 1px solid rgba(255, 255, 255, 0.14);
    flex-direction: column;
    padding: 16px;
    gap: 10px;
    display: none;
    box-shadow: 0 16px 40px rgba(0, 0, 0, 0.6);
  }
  .nav-links a {
    width: 100%;
    text-align: center;
    padding: 10px 16px;
  }
  .nav-links.open { display: flex; }
  .nav-toggle { display: flex; }

  .split { grid-template-columns: 1fr; gap: 28px; }
  .fact-strip { grid-template-columns: 1fr; }

  .diagram-block,
  .diagram-block.reverse {
    grid-template-columns: 1fr;
  }
  .diagram-block.reverse .diagram-desc { order: 1; }
  .diagram-block.reverse .diagram-frame { order: 2; margin: 24px auto 0; }
  .diagram-frame.narrow { max-width: 320px; margin: 0 auto; }

  .hero-meta {
    flex-direction: column;
    align-items: center;
    gap: 24px;
  }
  .team-grid { grid-template-columns: 1fr; }

  .ref-row {
    grid-template-columns: 32px 1fr;
  }
  .ref-go { display: none; }

  .scroll-top-btn {
    bottom: 24px;
    right: 20px;
    width: 44px;
    height: 44px;
  }
}